Forging of rings and similar parts



Filed May 14, 1958 3,046,653 FORGING F RINGS AND SIMILAR PARTS JosefMartinek, Brno, Czechoslovakia, assignor to Zavody presnehostrojirenstvi Lisen narodni podnik zavod Antonina Zapotockeho, Lisen,Czechoslovakia Filed May 14, 1958, Ser. No. 735,149 4 Qlaims. (Cl.29-552) This invention relates to methods of and machines for forgingrings and similar parts, for example, anti-friction bearing rings.

It is common practice to use as a starting material bars heated to theupsetting temperature. The end of the bar is forged in upsetting dies ofthe required shape. This operation is usually performed in two stages inthe same forging machine using two upsetting tools which are locatedeither above one another or side by side.

In the first stage, the heated end of the bar is preforged so that ashoulder is formed, the diameter of which corresponds to the requireddiameter of the ring. Simultaneously, a part of the bore of the ring ispre-forged. During the second stage, an upsetting mandrel completes theshaping of the bore and at the same time separates the rings from thebar. In some cases this separation is carried out as a separateoperation in a third stage.

With the known method, forging requires at least two working strokes ofthe machine. During this operation, the forge bar must be shifted fromone tool to the other and the tools must therefore be divided and mustopen simultaneously with the clamping device which clamps the bar whileit is being upset. As a result of this shifting of the bar, its heatedend quickly cools off and it must be frequently re-heated. The mechanismof the forging machine is complicated and its operation calls for heavywork by two men. Failures often occur.

One object of the present invention is to provide a method of forgingrings in which the pre-forming and finishing of the rings are carriedout during one stage only and during a single working stroke of the ram.

According to the present invention .a method of forging metal rings orlike parts comprises the steps of heating one end of a bar to anupsetting temperature, clamping the bar, upsetting the heated end of thebar within a die by the advance of a mandrel, forming a bore within theupset portion of the bar by the continued advance of the mandrel,unclamp ing the bar, separating the upset portion of the bar from theremainder of the bar by the continued movement of the mandrel andsimultaneously upsetting the said separated portion within the die bythe advance of an upsetting bushing to form said portion to its finalshape.

For a better understanding of these and other features of the inventionthere will now be described by way of example only anembodiment thereofwith reference to the accompanying drawings in which:

FIGURE 1 is a diagrammatic plan, partly in section, of a forging machinefor performing the method of the invention;

FIGURE 2 is an elevation of a cam for controlling the clamping of thebar to be upset;

FIGURE 3 is a detailed view illustrating part of the mechanism forfeeding the bar, and FIGURE 4 shows an alternative mechanism foractuating the clamping device.

In FIGURE 1, the parts of a forging machine are shown in the position inwhich they arrive at the end of the working stroke of a ram 5 which isreciprocated by mechanism not shown in the direction of the arrows3,046,653 Patented July 31, 1962 jaws 1 and 2 with the inner end of thebar in a predetermined position. tion, the ram 5 is at the opposite endof its stroke to that shown and commences to move in the direction of,

the arrow S towards a die-block 3. A follower roller 6 on a lever 7 thenmoves over a cam track 8a of a cam 8. The lever 7 is thus rocked andmoves the clamp jaw 1 to clamp the bar M against the clamp jaw 2. Theend of the trimming mandrel 4 upsets the end of the bar M within the diecavity 10 of the die block 3. When there is on the bar M a quantity ofmaterial upset by the trimming mandrel 4, which quantity is equal involume to that of the required forging, the follower roller 6 reachesthe end of the cam rise in the cam track 8 so that the lever 7 can rockto free the clamp 1 from the bar M. The ram 5 continues moving in thedirection S and the trimming mandrel 4 is forced through the upsetmaterial in the die cavity 10 and with the aid of a cutting edge 11 ofthe die block, separates the upset blank portion of the bar from theremainder of the bar. The ram 5 continues to move in the direction S sothat the face of the holder 12 of the trimming mandrel 4 engages theback face of the upsetting bushing 13 and moves this bushing in thedirection S. The upsetting face, that is the lefthand face in FIGURE 1,of the bushing 13 is larger than the open face of the die cavity 10 andengages the preforged separated blank 9 in the die cavity and upsets itinto the die cavity thus forming the material to its final shape. a

The depth of the die cavity may either be equal to the axial length ofthe required forging, or it may be less than that length. In the lattercase a flange will be formed around the forging between the bushing andthe die block.

Towards the end of the working stroke of the ram 5 the follower roller 6engages a shifting stop 15 and is moved by it over a second cam track 8bwhich is at a different level to the cam track 8a so that the roller thedie block, the upsetting bushing engages a stop 14' and is preventedfrom moving further in the directions with the ram and the trimmingmandrel. The trimmingmandrel is thus withdrawn from the forging which isheld back by the upsetting bushing and which falls from the machine.When the ram 5 reaches its starting position, the follower roller 6 ismoved by the spring 16 back onto the cam track 8a since both tracks 8aand 8b are at the same levelat the point then engaged by the followerroller 6.

The clamp jaws 1 and 2 are thus open during the return stroke of 'theram to allow of the bar end being fed forwards into the machine.

The bar M is fed by means of a clamp 22 actuated by a lever 20 which ispivoted at 21 and is connected by a link 17 to the ram 5. The end of thelever 20 carries a screw 19 on which is a nut 18 to which one end of thelink 17 is articulated.

The extent of feed of the bar can thus be adjusted by rotating the screw19 to move the nut 18 up or down and thus alter the effective length ofthe lever 20. The feed clamp comprises an abutment portion 22 andwedgeshaped jaws 23. The wedges 24 are mounted between the jaws 23 andthe abutment 22 and are connected by links 26 to the lever 20. Springs25 acting on the jaws 23 tend to separate them. During the workingstroke of the ram the lever 20 will be rocked counter-clockwise as Whenthe machine is put into operaseen in FIGURE 1 and will move the wedges24 to the left as seen in FIGURE 3 so as to free the jaws 23 from thebar. This movement is also transmitted to the clamp which moves as awhole to the left. During the return stroke of the ram, the wedges 24are moved to the right as seen in FIGURE 3 and wedge the jaws 23 againstthe bar so that it is fed to the right by the clamp.

The thin M is thus fed into its proper position before commencement ofanother forging operation.

FIGURE 4 shows an alternative arrangement for operating the clamp jaw 1.In this construction the follower roller 6 on the lever 7 is operated bya cam 28 mounted on the main operating shaft of the machine or on ashaft driven therefrom at the same speed.

I claim:

1. In a method of forging a metal ring and the like, the steps ofclamping an elongated bar having a longitudinal axis in such a mannerthat an end portion of said bar projects through an opening into a diecavity in an axial direction; moving a mandrel member into said cavityagainst the projecting end portion of said clamped bar in a directionopposite to said axial direction to displace the material of said endportion of said bar in a radially outward direction about said axisuntil said material partially fills said cavity and forms an annularblank about said mandrel; further moving said mandrel member in saidopposite direction and through said opening so as to sever said blankfrom the remainder of said bar, said mandrel member substantiallyconforming to said opening; and forcing said severed blank into said diecavity about said mandrel in said opposite direction until the blank isshaped into a ring conforming with said cavity.

2. A method of forging a metal ring and the like, comprising the stepsof heating an end portion of an elongated bar having a longitudinalaxis; clamping said bar in such a manner that said heated portion of.said bar projects through an opening into a die cavity in an axialdirection; moving a mandrel member into said cavity against theprojecting end portion of said clamped bar in a direction opposite tosaid axial direction to displace the material of said end portion ofsaid bar in a radially outward direction about said axis until saidmaterial partially fills said cavity and forms an annular blank aboutsaid mandrel; further moving said mandrel member in said oppositedirection and through said opening so as to sever said blank from theremainder of said bar, said mandrel member substantially conforming tosaid opening; and forcing said severed blank into said die cavityaboutsaid mandrel in said opposite direction until the blank is shapedinto a ring conforming with said cavity.

3. In a method of forging a metal ring and the like, the steps ofclamping an elongated bar having a longitudinal axis in such a mannerthat an end portion of said bar projects through an opening into a diecavity in an axial direction; moving a mandrel member into said cavityagainst the projecting end portion of said clamped bar in a directionopposite to said axial direction to displace the material of said endportion of said bar in a radially outward direction about said axisuntil said material partially fills said cavity and forms an annularblank about said mandrel, the volume of said blank being substantiallyequal to the volume of said cavity; further moving said mandrel memberin said opposite direction and through said opening so as to sever saidblank from the remainder of said bar, said mandrel member substantiallyconforming to said severed opening; and forcing said blank into said diecavity about said mandrel in said opposite direction until the blank isshaped into a ring conforming with said cavity.

4. In a method of forging a metal ring and the like, the steps ofclamping an elongated bar having a longitudinal axis in such a mannerthat an end portion of said bar projects through an opening into a diecavity in an axial direction; moving a mandrel member into said cavityagainst the projecting end portion of said clamped bar in a directionopposite to said axial direction to displace the material of said endportion of said bar in a radially outward direction about said axisuntil said material partially fills said cavity and forms an annularblank about said mandrel; further moving said mandrel member in saidopposite direction and through said opening so as to sever said blankfrom the remainder of said bar, said mandrel member substantiallyconforming to said opening; forcing said severed blank into said diecavity about said mandrel in said opposite direction until the blank isshaped into a ring conforming with said cavity; retracting said mandrelmember and said ring in said axial direction; and axially advancing saidbar into said cavity.

References Cited in the file of this patent UNITED STATES PATENTS819,844 Briede May 8,1906 1,151,753 Bates Aug. 31, 1915 1,314,037 AmbergAug. 26, 1919 1,456,597 Hughes May 29, 1923 1,714,661 Crawford et al.May 28, 1929 1,749,334 Georg Mar. 4, 1930 2,874,460 Riethmuller et al.Feb. 24, 1959

